Hydraulic door actuator



g- 12, 1952 c. G. G. GROUP 2,606,761

HYDRAULIC DOOR ACTUATOR Filed June 29, 1949 4 Sheets-Sheet l INVENTOR.CHARLES 6'. 6. GROUP A g- 1952 c. G. G. GR OUP HYDRAULIC DOOR ACTUATOR 4Sheets-Sheet 2 Filed June 29, 1949 FIG. 3

FIG/4 INVENTOR. CHARLES G. 6. GROUP g- 12, 1952 c. G. G. GROUP 2,606,761

HYDRAULIC DOOR ACTUATOR Filed June 29, 1949 4 Sheets-Sheet 3 INVENTOR.

CHARLES 6. 6. GROUP Qaz 12, 1952 c. G. G. GROUP HYDRAULIC. DOOR ACTUATORFiled June 29, 1949 4 Sheets-Sheet 4 FIG. 7

' INVENTOR. CHARLES G 6'. GROUP FIG. 8

Patented Aug. 12, 1952 UNITED; STATES PATENT -.o FF.IcEif-f .Charles G.G. Group, Cleveland, Ohio Application June 29, 1949, Serial Nc.102, 70;I

This invention relates "to door openers and more particularly to a dooropener hydraulically operated by a weight on a platform.

The desirability for an'automatic door opener has long been present.Among the first attempts to fill this need is .thegate which opens uponpulling a rope on the end of a long lever.

Since that time, many more attempts have been made with more or lesssuccess.

These attempts include those openers which require electronic circuitsfor their action. These may be set off either by sound, as from a tunedhorn or by the interruption of a light beam focused on a photoelectriccell. These, however, require an electronic relay and a motor and are,therefore, somewhat expensive and are subject to tube failures andthelike in the relay.

Other attempts have been based on hydraulic mechanism. In order toobtain pressure for these systems, it was common to use the pressure ofcity water or that supplied by a separate pump. This gave an adequatesupply of fluid to operate the actuator piston through its relatively 1Claim. (Cl. 26837) long required stroke. In general, however, theserequired the manual turning of a valve which was mounted on a postbeside the driveway, requiring that the automobile be run suflicientlyclose to that valve to reach it, or that the driver disembark which isthe maneuver sought to be avoided.

Theprincipal reason for the lack of a simple door opener operated by theweight of the vehicle approaching the door has been the fact that a longstroke is required .of the operating piston, and this piston must be ofsuificient area to supply force enough to startthe opening of the dooreven when it sticks somewhat. This requires a fairly large quantity ofoil or other hydraulic fluid, and in order to obtain this volume, thepressure generating cylinder must be sufiiciently large to deliver thefull quantity. However, this leads to a severe problem. The volumemust'be obtained either by lengthening the stroke or increasing thediameter. Lengthening the stroke, in general, leads to a situation wherethe car must be tilted uncomfortably to operate the device; Increasingthe piston diameter on the other hand decreases the available pressurefor a given weight to the point where the force of the actuator pistonmay be insufficient to over- 4 the a highstarting pressure and after thedoor is 4 2 started opening, sufiicient volume ofifluid issueplied at alower pressure'to continue theopening of the door. 1 1 A more complete"understanding of my invention, and the invention its'elf, may be hadfrom reference to the accompanying figures'in'which: Fig.1 is a viewpartlyrin section-showing-the actuator of my invention; r A V Fig. 2 isa front view of'the pressure supply mechanism of my invention'showingtheipre's surecylinders in section;

Fig. 3 is a side View of the pressure sup'ply s'y's tem;

Fig. 4 is a side view of an alternative einbo'di ment of my pressuresupply system;

Fig. 5 is a sectional view'showi'ng anotheralternative form of thepressure supply system of my invention; v

Fig. 6 is a view similar'to" Fig."5' Sh'0Win'g'ls'ti11 anotheralternative form of the-pressure supply system of my invention;

Fig. 7 is a view showing my "inventionasfa'p plied to one type of gate;

Fig. 8 is a sectional viewr'sho'wing my inven, tion as applied to atilting door; and

Fig. 9 is a section view from above "the door showingthe mounting means.

Briefly, my invention comprisesaniactuating cylinder which may beadapted to operate any'of several well knowntypes'of doors. Inthe main;these doors are cable operated, and therefore I have shown the device asadapted to wind :9.

cable on a drum. It will be apparent, however, that my invention neednot'be so limited; The fluid under pressure for this cylinder issupplied from a plurality of pressure cylinders. the simplest form,there are two cylinders engaged by a" platform over which the vehicle isdriven. These would be arranged so'tha't "the platform would engage onesome time before engaging the other. Since the full weight on the wheelthen on the platform is first'applied to a single piston, the pressurewill be quite great at first; the platform engages the second'piston,since the eight. will then be. divided between the two. i. e., overtwice the piston area if the pistons "are of equal size, the pressurethen is halved. How'- ever, since the door has already been started bythe high pressure, less pressure is required to continue the openingprocessand the required volume is obtained by the use of the twocylinders. Several variations of this device areshown in the figures andmore fully described below. The actuator cylinder of my device is bestshown in Fig. 1 with its mounting and'the-driim for connection to cableoperated gates or doors. The cylinder II is mounted on a plate l2 whichis adapted to be fastened to the wall of the building 'or gate post. Acable l3 extends from the rod ll of the piston 15 around a pulley italso pivotally mounted on the plate [2. This pulley carries a drum l1preferably of larger diameter than the pulley, on which the operatingcables l8of the door may be wound. From the pulley [6 the cable 13passes to a point where it is fastened to a spring I9 adapted to keeptension in the cable and to return the piston IE to its top position inthe cylinder II when the fluid pressure is released.

A simple valve system may be used in this cylinder to provide forrelatively quick opening and slow closing action. The main fluid supplyline 2| leads into the cylinder through a check valve 22. This valve maybe of any usual type, it being shown diagrammatically for the purpose ofthis description. .This valve 22 allows the fluid to enter thecylinderfreely, but when the pressure is released, the valve closescausing the fluid to passthrough a bypass line 23. A valve 24 in thisline regulates the speed at which the fluid'returns to the pressuresource and therefore regulates the closing speed of the doors. It isapparent this valve 24 could be of other types than the needle valveshown and might be a spring loaded, normally closed valve which wouldhold the door open until released manually from wit in the garage.

The pressure supply system may be made in several different em odiments,several of which are shown in Figs. 2 through 6. In each it willbenotedthat there is a plurality of cylinder and pistonlassemblies, atleast one piston of which is en aged before the others. Morespecifically, in the. embodiment of Figs. 2 and 3, the pressure systemcomprises a base 2! on which are mounted the cylinders 28 and 29. Thehigh pressure cylinder 28 is shown with a smaller diameter than the lowpressure cylinder 29 although as previously described, they might wellbe of equal diameter. With the different diameters as shown, the ratioof the high pressure to low pressure will be greater than 2:1 whichwould be the ratio were the diameters equal. A high pressure piston3lland a low pressure piston 3| are disposed in'their respectivecylinders 28 and 29; the

operating rods 32 and 33 extending through the upper heads 34 and '35 ofthe cylinders. cylinders 28 and 29 are connected to a common pressureline 36 which feeds into the supply line2l. V

' A lever 31 is hinged to the base 21 at 39 in position to engage therods 32 and 33. This lever is formed such that in its downward travel itwill engage the high pressure piston rod 32 sometime before the lowpressure rod 33. Thus the high pressure piston 39 is forced down by thefull weight on the lever 31 causing a high pressure in the line 36 andtherefore in the actuating cylinder H. The piston 31 is merely forced upagainst the upper head 35 during this part of the stroke. Asthelever'comes down because of the travel of the piston in the actuatingcylinder II, it engages the rod 33 and then the force on the lever isbalanced between two pistons of much'larger area than the first onealone. As a result, the pressure is decreased, as described above, but

the door will continue to open.

The force on the lever 31 is preferably the result of the weight of anautomobile or other vehicle being driven onto the lever 31. To ac- Thecomplish this, I provide ramps 40 adapted to be placed in one lane of adriveway. These ramps are pivoted to a platform portion 41 of the lever31. Since the lever will necessarily tilt laterally about its hinge 38,it is desirable that the joint of the ramps 49 to the platform 4! be auniversal swivelling joint. This may be any of several types of joints,but for this purpose, it is illustrated as a ball and socket joint. 43.,Rollers 44 may be provided pivoted to the lower end of the ramp 49 toallow the ramps to move longitudinally when the lever 31 moves downward.

The ramps preferably are of such length that the front wheels of anautomobile will still be on one ramp when the rear wheels start onto theother. This will insure pressure on the lever 31 at all times during thepassage of the vehicle and thus the length of time of continuouspressure to open the door will be greater.

The lever in this embodiment may be extended as shown to provide a footpedal 41. This extension must be long enough so that a weight ofapproximately pounds on it will open the door easily. It is thenpossible for the doors to be opened from the outside merely by steppinonto the foot pedal .1.

The parts are returned to their normal position by hydraulic actionresulting from the T81.

turn of the actuating piston i5 to its original position by the spring19.

An alternative embodiment which will eliminate the need for the ball andsocket joint'43 is shown in Fig. 4. In this embodiment the cylinders 28and 29 are spaced longitudinally of the device rather than laterally;the high pressure cylinder 28 being placed under the ramp 43 firstengaged by the vehicles wheel. The platform 49 in this embodiment issupported by springs 58 at each of its corners. In'order to prevent anyexcept a vertical motion, sliding guides 52yare provided. These may welltake the form of a telescoping rectangular box mounted on the platform49, although the guides may not be necessary on the sides since therewill be little lateral force. The ramps 40 in this embodiment are hingedto the platform 49 by a simple straight hinge 53 since the platform doesnot necessarily tilt laterally.

In operation this device is somewhat different from that previouslydescribed, althoughthe principle is the same. In this embodiment, as thevehicle approaches and starts up the left hand (Fig. 4) ramp 40, thesprings 59 on that side of the platform are compressed, and-the rampengages and forces downward the operating rod 32 of the high pressurepiston 33. As the vehicle rolls up the ramp onto the platform 49, thesprings on the other side of the platform are compressed and the lowpressure cylinder and piston assembly are operated to provide the sameresult as in the prior embodiment. The piston rods 32 and 33 arenecessarily placed close to the hinge points 43 and, therefore, theweight of the overhanging part of the ramp 4B is sufiicient for keepingthe ramp in contact with the ground instead of pivoting around thepiston rod when the vehicle is on the platform 49 or the opposite ramp.A stop 54 is also provided to prevent too great force from being appliedto the cylinders. This embodiment is returned to its original positionprimarily by corner springs 59 leaving only the pistons to be pushed upby the hydraulic'sys- A third embodiment using concentric piston andcylinder means is illustrated in Fig. 5. In

this embodiment a large cylinder 53 is mounted onthe base 54 to whichthe pressure line 2| is connected. A piston 55 is operably dispos'edinthis cylinder and is held within the cylinder'by a ring" 56 fixed tothe-top of the cylinder by screws 5Z1. While they are not shown, it willb'e meanest-wh those-skilled in the art that-piston rings and packingglands :oro'then types of sealing mechanism may be provided to preventleakage of fluid from thiscylinder.

A smaller cylinder 58 is formed in the piston 55 to provide the highpressure necessary for startin'g: 'A piston '5-9 havinga-stem or rod601s slidably disposed in'the'smaller cylinder with the rod extendingthrough guide portion 62 formed in the large piston. A bar 63 extendinglaterally is fixed to theend of the rod 60 by some means such aswelding. Ears 64 extending upwardly from this bar receive the pins 65 onwhich both ramps 40 may be pivoted in the well known manner of a hinge.

The operation of this embodiment is similar to that of those previouslydescribed. Since the ramps are hinged at a common line over the centerline of the cylinders, there are no overhanging loads on the piston, andthere will he, therefore, less tendency to binding of the piston in thecylinder. As the small piston reaches the end of its stroke, the bar 63engages the top of the large piston 55 forcing it down with an effectexactly similar to the action of the two pistons in the prior describedembodiments.

Still another embodiment is shown in Fig. 6. In the embodiment shown,the cylinder 61 is formed with a top 58 and guide portions 69,althoughthese portions could be formed from a separate piece andattached to a cylinder similar to that of the embodiment just previouslydescribed.

The operating piston iii in this cylinder has a stem H slidablyjournalled in the guide 69. Above this, I have shown a necked-downsection 12 extending upward to a small piston I3. A small cylinder 14 isslidably journalled on this piston 13 and carries a stop 15 fixed to thecylinder i4 and slidably journalled on the neckeddown portion '12. Itwill be recognized that, if the small piston '23 were made somewhatlarger than the stem H, there would be no need for a necked-down section12 as shown. A compression spring 16 may be disposed in the smallcylinder 14 between the head I! of the cylinder and the piston 13. Thisspring is held in a recess 18 in the cylinder so that before it iscompletely compressed, the cylinder presses on the piston to force thelarge piston 16 downward. A passageway ?9 is formed through the pistonsand their stemsto connect the two cylinder chambers.

The head ll of the small cylinder M may be formed with extensionsthereon similar to the bar 63 of the previously described embodiment.Ears 65 holding the pin 65 on which the ramps 48 are journalled areexactly similar to those previously described.

The operation of this embodiment of pressure apply system is the same asthat described above. As the liquid is forced through the passageway 19into the tube 2| to the actuator, the cylinder l4 reaches the end of itstravel and engages the stem of piston 19, forcing that piston downwardwith the same effect as previously described.

The application of my device to a lifting type gate is illustrated byFig. 7. A gate 82 formed of a series of parallelograms having pinned,pivotal joints is hung on a post 83. The actuator as- 6 sembly ofmy-zdeviceiis calso ffirmly mounted ion this post. The cable lli,'whichiis adapted to opcrate the gate :82, :extends from. the drum .11.over. a pulley 8'4 Tait thetop "of 'thepost 83 and is fastened at itsother end to an eye 85 suitably fixed thegate.

As the vehicle approaches the gate, the actua-, tor is operated bythepressuresupply system as previously described, and the cable 18 iswoundon the drum IT. This causes the gate tot-rise to the positionshownby the dashedlinesin Fig. 7. As the vehicle passes, the gate willclose slowly at a rate dependent on the adjustment of the bleed valve-24 (Fig. 1). It is apparent that a "p're's'sure system could be put atboth sides of the 'gate merely by using a T connection in the pressureline 2|. This would make it possible to open the gate upon approachingfrom either direction.

A simple application of my device to an overhead garage door isillustrated in Figs. 8 and 9. The door 81 is hung from brackets 88 fixedto an axle 89. These brackets are preferably welded to the axle toprevent any relative motion therebetween. This axle is journalled atboth ends in a bearing carried by a housing 99 mounted on a bracket 9|which, in turn, may be fastened to the studdings or corner posts 92 onthe inside of the garage. A pulley 93 is fixed to the axle 89 in aposition where it may be operated by the actuator of my device. Sincethe door, and therefore the pulley, moves through only a quarter of aturn, it is apparent that a larger pulley can be used for cable operateddoors.

I prefer this type of door because there is little or no twisting strainon the door as it is being operated, all that strain being taken in theaxle 89. However, this description is not to be interpreted as limitingthe invention to applications of my device to this particular type ofdoor. It will also be apparent that, if a single deviceis not effectiveto open the door, a pair could be used simply by mounting the otheractuator on the opposite side of the door and another pressure supplyunit in the other runway of the drive. However, for the ordinary usage,such double installation will not be required.

Other embodiments will be obvious to those skilled in the art. Forexample, the cylinders might be placed individually in a staggeredarrangement in a single path of the driveway, or preferably one in eachpath so that both. would be operated at the same time, although the highpressure cylinder would be started first. It is also apparent that morecylinders could be used provided the effect were the same.

Thus, it is apparent that I have provided a door opener which isinexpensive and sturdy, requiring no auxiliary source of energy, andcapable of opening a door or gate fully merely by the Weight of anautomobile.

Having thus described my invention, I am aware that numerous departuresmay be made therefrom without departing from the spirit or scope of myinvention.

I claim:

Operating means for a hydraulic door opener comprising a base, aplatform pivotally attached along one end to said base and having aportion extending over the base, the parts of which are parallel to thebase transversely of the platform, a plurality of cylinder means mountedon said base at different distances from the pivotal connection, thecylinder nearest the pivotal connection being of smaller diameter thanthe others, pistons slidably disposed in said cylinders, oper- 7ating'means for said pistons adapted to be engaged successively by saidplatform in order of distance from said pivotal connection, and rampmeans connected to said platform by a universal joint.

CHARLES G. G. GROUP.

REFERENCES CITED UNITED STATES PATENTS Number V Name Date 1,421,002Hagen June 27, 1922 1,921,008 Shinn Aug. 8, 1933 Number Number 289,158

8 Name Date Engel Nov. 13, 1934 Cox Oct. 20, 1936 Miller July 18, 1939-Staude Aug. 8, 1939 Dodge -1 July 2, 1940 Haynes Aug. 18, 1942 EdgemondDec. 28, 1943 Forbes Feb. 8, 1944 FOREIGN PATENTS Country Date GreatBritain Oct. 19, 1927 France Dec. 24, 1929

